In vitro antibacterial and antibiotic-potentiation activities of five edible plant extracts and mode of action against several MDR Gram-negative phenotypes

2020 ◽  
Vol 4 (1) ◽  
pp. 1-14
Author(s):  
Carine M.N. Ngaffo ◽  
Simplice B. Tankeo ◽  
Michel-Gael F. Guefack ◽  
Brice E. N. Wamba ◽  
Paul Nayim ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Bioactive Compounds ◽  
Plant Extracts ◽  
Theobroma Cacao ◽  
Efflux Pumps ◽  
Phoenix Dactylifera ◽  
Food Plants ◽  
Proton Pumps ◽  
Gram Negative ◽  
E Coli

Abstract Background: Bacterial infections involving the multidrug resistant (MDR) strains are among the top leading causes of death throughout the world. Healthcare system across the globe has been suffering from an extra-ordinary burden in terms of looking for the new and more potent antimicrobial compounds. The aim of the present study was to determine the antibacterial activity of some Cameroonian edible plants (Garcinia lucida bark, Phoenix dactylifera pericarps, Theobroma cacao pod, Solanum macrocarpon leaves and Termitomyces titanicus whole plant) and their antibiotics-potentiation effects against some MDR Gram-negative bacteria phenotypes expressing efflux pumps (Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa and Providencia stuartii strains). Methods: The antibacterial activities of plant extract alone and in combination with usual antibiotics were carried out using the micro-dilution method. The effects of the most active plant extract (Garcinia lucida bark) on H+-ATPase-mediated proton pumps and on bacterial growth kinetic were performed using experimental protocols, while qualitative reference methods were used to highligh the major groups of secondary metabolites present in the extracts. Results: Qualitative phytochemical screening of plant extracts indicated that all analysed secondary metabolites were present in Theobroma cacao and Termitomyces titanicus while one (saponins) of them was absent in Garcinia lucida and Solanum macrocarpon. Only three of them (polyphenols, flavonoids and saponins) were detected in Phoenix dactylifera. Antibacterial essays showed that G. lucida was the most active plant as it inhibited the growth of all studied bacteria with strong activity (MIC<100 µg/mL) against E. coli ATCC8739, significant activity (100≤MIC≤512 µg/mL) against 80% of bacteria and moderate activity (512<MIC≤2048 µg/mL) against E. coli AG100A and E. aerogenes (EA289 and CM64). It was followed by T. cacao and S. macrocarpon extracts which exhibited an antibacterial potential against 95% and 80% of bacterial strains, respectively. These three extracts exhibited a bactericidal effect on a few bacteria. Extracts from T. titanicus and P. dactylifera were less active as they moderately (512<MIC≤2048 µg/mL) inhibited the growth of 35% and 10% of bacteria. All extracts selectively potentiated the activities of all antibiotics with improvement activity factors (IAF) ranging from 2 to 256. G. lucida, T. cacao and S. macrocarpon potentiated the activities of 100%, 89% and 67% of antibiotics respectively against more than 70%, suggesting that they contain bioactive compounds which could be considered as efflux pumps inhibitors. Whereas T. titanicus and P. dactylifera improved the activities of almost 40% and 20% of antibiotics, respectively. This increase of activities also characterizes synergistic effects between antibiotics and these bioactive compounds. G. lucida extract at all tested concentrations, strongly inhibited the growth of bacterial strain E. coli ATCC8739 and exhibited an inhibitory effect on this bacterial H+-ATPase-mediated proton pumps increasing the pH of the medium. Conclusion: The overall results indicated that food plants among which G. lucida, T. cacao and S. macrocarpon could have a benefit interest in combatting resistant types of bacteria. Keywords: Food plants; infectious diseases; MDR bacteria; efflux pumps; antibiotics; secondary metabolites.

Phytochemical analysis and antibiotic-modulating activity of Cocos nucifera, Glycine max and Musa sapientum methanol extracts against multidrug resistant Gram-negative bacteria

2021 ◽  
Vol 4 (2) ◽  
pp. 1-12
Author(s):  
Carine M.N. Ngaffo ◽  
Simplice B. Tankeo ◽  
Michel-Gael F. Guefack ◽  
Paul Nayim ◽  
Brice E.N. Wamba ◽  
...  
Keyword(s):  
Glycine Max ◽  
Bioactive Compounds ◽  
Cocos Nucifera ◽  
Efflux Pumps ◽  
Multidrug Resistant ◽  
Significant Activity ◽  
Gram Negative ◽  
E Coli ◽  
Bactericidal Effects ◽  
Different Parts

Background: The rapid emergence of multidrug resistant (MDR) bacteria is occurring worldwide, endangering the efficacy of antibiotics, which have transformed medicine and saved millions of lives. Antibiotic-resistant infections are already widespread in the Sub-Saharan Africa and across the globe. To extend the search for new and more efficient antimicrobial drugs from natural sources, this work has been carried out to study the phytochemical composition and the antibacterial activities of some Cameroonian dietary plants (Cocos nucifera, Glycine max and Musa sapientum) against several MDR Gram-negative strains including Escherichia coli, Enterobacter aerogenes, Providencia stuartii, Klebsiella pneumoniae, Pseudomonas aeruginosa species expressing efflux pumps. Methods: Phytochemical screening of plant extracts was performed using qualitative standard methods and the antimicrobial assays of these extracts alone and in combination with antibiotics were done using serial 96-wells microplate dilution essays. Results: Each plant extract contained at least three mean classes of secondary metabolites. Glycine max, epicarps, leaves and bark of C. nucifera as well as mesocarps of M. sapientum contained each alkaloids, polyphenols, flavonoids, and triterpenes. Moreover, steroids were also found in G. max, steroids and saponins in epicarps and saponins in bark of C. nucifera. Meanwhile epicarps from M. sapientum contained only polyphenols, flavonoids and saponins. Antibacterial assays showed that different parts of C. nucifera were more active than other extracts. Their minimal inhibitory concentrations (MICs) varied from 128 to 2048 µg/mL. The bark part presented the highest antibacterial potential inhibiting the growth of 90% of strains with significant activity (100≤MIC≤512 µg/mL) against 50% of them (three E. coli, four E. aerogenes and three K. pneumoniae). It showed bactericidal effects (MBC/MIC≤4) on 45% of the same bacterial species. It was followed by epicarps and leaves parts which exhibited an inhibitory power against 75% and 60% of bacteria with significant activity on 40% and 20% of them respectively. They also showed bactericidal effects on E. coli ATCC8739 for epicarps extract and E. coli ATCC8739 and P. stuartii NEA16 for leaves extract. Extracts from G. max were less active and those from mesocarps and epicarps of M. sapientum did not showed any activity on all studied bacteria. Bark and epicarps extracts of C. nucifera potentiated the activities of all used antibiotics against at least 70% of bacteria while leaves extract exhibited this effect improving the activities of 67% of antibiotics with improvement activity factors (IAF) ranging from 2 to 256 suggesting that they contain bioactive compounds which could be considered as efflux pumps inhibitors. Extracts from G. max, epicarps and mesocarps of M. sapientum enhanced the inhibitory potential of 56%, 34% and 23% of antibiotics respectively against at least 70% of studied bacteria. These increases of activities also characterize synergistic effects between antibiotics and bioactive compounds of plants. Conclusion: The findings of this work suggest that infections by resistant bacteria can be treated using different parts of C. nucifera as an alternative to commonly used antibiotics.

Antibiotic-potentiation activities of three animal species extracts, Bitis arietans, Helix aspersa, and Aristaeomorpha foliacea and mode of action against MDR Gram-negative bacteria phenotypes

2020 ◽  
Vol 4 (1) ◽  
pp. 1-15
Author(s):  
Michel-Gael F. Guefack ◽  
Simplice B. Tankeo ◽  
Carine M.N. Ngaffo ◽  
Paul Nayim ◽  
Brice E.N. Wamba ◽  
...  
Keyword(s):  
Animal Species ◽  
Efflux Pumps ◽  
Multidrug Resistant ◽  
Proton Pumps ◽  
Gram Negative Bacteria ◽  
Significant Activity ◽  
Bacterial Strains ◽  
Gram Negative ◽  
E Coli ◽  
Aristaeomorpha Foliacea

Abstract Background: In recent years, drug resistance to human pathogenic bacteria has been commonly reported from all over the world. As antimicrobial activities of most medicinal plants and antibiotics have been already explored, it is more important to make investigations on animal species mainly invertebrates which could constitute an efficient source of antimicrobial molecules. This work was aimed at contributing to the fight against microbial resistance through the study of antibacterial potential of three animal species (Helix aspersa, Bitis arietans, Aristaeomorpha foliacea) on several multidrug-resistant (MDR) Gram-negative strains overexpressing efflux pumps including Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa. Methods: The microdilution technique was used to evaluate the antibacterial activities of the tested samples by determining their minimal inhibitory concentrations (MICs), as well as the effect of their combination with antibiotics. Studies on the mechanisms of action of the most active sample, dried Bitis arietans extract, was carried out using standard methods for evaluating the effects of this extract on bacterial H+-ATPases-mediated proton pumps and on bacterial growth kinetics. In this latter case, the optical density was read spectrophotometrically. Results: Zoochemical screening indicated the presence of protein constituents and alkaloids and the absence of other metabolites in all tested extracts. Dried B. arietans showed the best antibacterial activity by inhibiting the growth of 90% of studied bacterial strains with MICs ranging from 128 to 2048 μg/ml. Moreover, this extract presented a significant activity (100≤MIC≤512 µg/ml) against 35% of bacteria that are E. coli (ATCC8739, AG100ATet, MC4100), E. aerogenes EA27, K. pneumoniae ATCC11296, P. aeruginosa (PA01, PA124) and a moderate activity (512<MIC≤2048 µg/ml) against 55% of studied bacteria. It was followed by fresh B. arietans which inhibited the growth of 65% of bacteria with significant activity on three bacteria (E. coli ATCC8739, E. aerogenes ATCC13048 and K. pneumoniae ATCC11296. These two extracts showed bactericidal effects on many strains. The other extracts samples selectively exhibited an antibacterial activity against less than 40% of strains. All samples potentiated the activity of at least 56% of used antibiotics against at least 70% of studied bacterial strains. B. arietans extracts at MIC/2 and MIC/4 mostly improved the activities of more than 78% of antibiotics on at least 70% of bacteria with improvement activity factors (IAF) ranging from 2 – 128 suggesting that this animal contains bioactive compounds which could act as efflux pumps inhibitors. Bacterial growth kinetic study showed that when treated with dried B. arietans extract (the most active sample) at different concentrations MIC/2, MIC and 2xMIC, the growth of tested bacteria (E. coli ATCC8739) decreased respectively when the concentrations increased. Furthermore, this extract inhibited the H+-ATPase-mediated proton pumps of this bacterium increasing the pH values. Conclusion: Results obtained in the present work provide interesting data for the use of dried B. arietans extract and invertebrates in general in the traditional therapy for the treatment of bacterial infections involving multidrug-resistant phenotypes. Keywords: Gram-negative bacteria; multidrug resistance; efflux pumps; infectious diseases; animal species; secondary metabolites.

scholarly journals Characterization of a Novel Pyranopyridine Inhibitor of the AcrAB Efflux Pump of Escherichia coli

2013 ◽  
Vol 58 (2) ◽  
pp. 722-733 ◽  
Author(s):  
Timothy J. Opperman ◽  
Steven M. Kwasny ◽  
Hong-Suk Kim ◽  
Son T. Nguyen ◽  
Chad Houseweart ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Efflux Pump ◽  
Efflux Pumps ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Resistance Nodulation Division ◽  
Rnd Efflux Pumps ◽  
Acrab Efflux Pump

ABSTRACTMembers of the resistance-nodulation-division (RND) family of efflux pumps, such as AcrAB-TolC ofEscherichia coli, play major roles in multidrug resistance (MDR) in Gram-negative bacteria. A strategy for combating MDR is to develop efflux pump inhibitors (EPIs) for use in combination with an antibacterial agent. Here, we describe MBX2319, a novel pyranopyridine EPI with potent activity against RND efflux pumps of theEnterobacteriaceae. MBX2319 decreased the MICs of ciprofloxacin (CIP), levofloxacin, and piperacillin versusE. coliAB1157 by 2-, 4-, and 8-fold, respectively, but did not exhibit antibacterial activity alone and was not active against AcrAB-TolC-deficient strains. MBX2319 (3.13 μM) in combination with 0.016 μg/ml CIP (minimally bactericidal) decreased the viability (CFU/ml) ofE. coliAB1157 by 10,000-fold after 4 h of exposure, in comparison with 0.016 μg/ml CIP alone. In contrast, phenyl-arginine-β-naphthylamide (PAβN), a known EPI, did not increase the bactericidal activity of 0.016 μg/ml CIP at concentrations as high as 100 μM. MBX2319 increased intracellular accumulation of the fluorescent dye Hoechst 33342 in wild-type but not AcrAB-TolC-deficient strains and did not perturb the transmembrane proton gradient. MBX2319 was broadly active againstEnterobacteriaceaespecies andPseudomonas aeruginosa. MBX2319 is a potent EPI with possible utility as an adjunctive therapeutic agent for the treatment of infections caused by Gram-negative pathogens.

scholarly journals A Study the Effect of TiO2 Nanoparticles Combination with Antibiotics and Plant extracts Against Some Gram Negative Bacteria

2016 ◽  
Vol 13 (3) ◽  
pp. 425-434
Author(s):  
Baghdad Science Journal
Keyword(s):  
Titanium Dioxide ◽  
Acinetobacter Baumannii ◽  
Tio2 Nanoparticles ◽  
Plant Extracts ◽  
Salvia Officinalis ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Origanum Majorana ◽  
Arctium Minus

Titanium dioxide TiO2 has been widely utilized in cleaning and sterilizing material for many clinical tools sanitary ware, food tableware and cooking and items for use in hospitals. Titanium dioxide TiO2 non toxicity and long term physical and chemical stability. It has been widely used decomposition of organic compounds and microbial organisms such as cancer cell, viruses and bacteria as well as its potential application in sterilization of medical devices. The aim of the study the effect of titanium dioxide TiO2 on some Gram negative bacteria and study their effects on some virulence factors and chromosomal DNA.In this study, we obtained (E. coli ? Proteus mirabilis, Proteus vulgaris ? Pseudomonas aeruginosa ? Klebsiella pneumonia and Acinetobacter baumannii) from Al-Emamain Al-Kadhemain Medical City Hospital in Baghdad. Samples collection were carried out from 1 April to 30 June 2014. Study the effect of (plant extraction and Antibiotic) alone and combination with Titanium dioxide TiO2 on bacteria growth. And study the effect of Titanium dioxide TiO2 on biofilm layer and chromosomal DNA.Combinations of TiO2 nanoparticle with water and alcohol extracts of plant (Salvia officinalis ?Arctium minus, Origanum majorana and Anabasis syriaca) gave synergistic results against the gram negative bacterial isolates.A Synergism effect was observed in combination of Ciprofloxacin with Titanium TiO2 nanoparticles toward all Gram negative bacteria. Also a high efficiency was observed when TiO2 nanoparticles mixed with Amikacin toward all isolates except Acinetobacter baumannii and E. coli3. While the results of mixing TiO2 nanoparticles with Cephalothin indicate highly efficiency toward all isolates except Pseudomonas aeruginosa.The combination of plant extracts (Salvia officinalis ? Arctium minus ? Origanum majorana and Anabasis syriaca) with TiO2 nanoparticles was appear to be damaged to E. coli chromosomal DNA.The study showed the ability of nanoparticles TiO2 to inhibition of the layer Biofilm to all isolates of bacteria at concentrations (1, 1.5) µg/ ml.Conclude from this study we can be used TiO2 nanoparticles to kill some types of bacteria

scholarly journals Impaired Efflux of the Siderophore Enterobactin Induces Envelope Stress in Escherichia coli

2019 ◽  
Author(s):  
Randi L. Guest ◽  
Emily A. Court ◽  
Jayne L. Waldon ◽  
Kiersten A. Schock ◽  
Tracy L. Raivio
Keyword(s):  
Escherichia Coli ◽  
Nadh Dehydrogenase ◽  
Enteric Bacteria ◽  
Efflux Pumps ◽  
Multidrug Efflux ◽  
Gram Negative ◽  
E Coli ◽  
Multidrug Efflux Pumps ◽  
Pathway Activation ◽  
Envelope Stress

AbstractThe Cpx response is one of several envelope stress responses that monitor and maintain the integrity of the gram-negative bacterial envelope. While several conditions that are known or predicted to generate misfolded inner membrane proteins activate the Cpx response, the molecular nature of the Cpx inducing cue is not yet known. Studies have demonstrated that mutation of multidrug efflux pumps activates the Cpx response in many gram-negative bacteria. In Vibrio cholerae, pathway activation is due to accumulation of the catechol siderophore vibriobactin. However, the mechanism by which the Cpx response is activated by mutation of efflux pumps in Escherichia coli remains unknown. Here we show that inhibition of efflux by deletion of tolC, the outer membrane channel of several multidrug efflux pumps, activates the Cpx response in E. coli as a result of impaired efflux of the siderophore enterobactin. Enterobactin accumulation in the tolC mutant reduces activity of the NADH oxidation arm of the aerobic respiratory chain. However, NADH dehydrogenase I, NADH dehydrogenase II, and cytochrome bo3 do not contribute to Cpx pathway activation in the E. coli tolC mutant. We show that the Cpx response down-regulates transcription of the enterobactin biosynthesis operon. These results suggest that the Cpx response promotes adaptation to envelope stress in enteric bacteria that are exposed to iron-limited environments, which are rich in envelope-damaging compounds and conditions.

scholarly journals Myxobacteria as a Source of New Bioactive Compounds: A Perspective Study

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1265
Author(s):  
Mudasir Ahmad Bhat ◽  
Awdhesh Kumar Mishra ◽  
Mujtaba Aamir Bhat ◽  
Mohammad Iqbal Banday ◽  
Ommer Bashir ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Secondary Metabolites ◽  
Bioactive Compounds ◽  
Polyketide Synthases ◽  
Fruiting Bodies ◽  
Natural Sources ◽  
Gram Negative ◽  
Wide Range ◽  
New Antibiotics ◽  
Derivatives Of

Myxobacteria are unicellular, Gram-negative, soil-dwelling, gliding bacteria that belong to class δ-proteobacteria and order Myxococcales. They grow and proliferate by transverse fission under normal conditions, but form fruiting bodies which contain myxospores during unfavorable conditions. In view of the escalating problem of antibiotic resistance among disease-causing pathogens, it becomes mandatory to search for new antibiotics effective against such pathogens from natural sources. Among the different approaches, Myxobacteria, having a rich armor of secondary metabolites, preferably derivatives of polyketide synthases (PKSs) along with non-ribosomal peptide synthases (NRPSs) and their hybrids, are currently being explored as producers of new antibiotics. The Myxobacterial species are functionally characterized to assess their ability to produce antibacterial, antifungal, anticancer, antimalarial, immunosuppressive, cytotoxic and antioxidative bioactive compounds. In our study, we have found their compounds to be effective against a wide range of pathogens associated with the concurrence of different infectious diseases.

SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF 3-FORMYL INDOLE BASED SCHIFF BASES

2018 ◽  
Vol 7 (6) ◽  
Author(s):  
Singh Gurvinder ◽  
Singh Prabhsimran ◽  
Dhawan R. K.
Keyword(s):  
Antimicrobial Activity ◽  
Spectral Analysis ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Biological Evaluation ◽  
Fungal Strain ◽  
Bacterial Strains ◽  
Standard Drug ◽  
Gram Negative ◽  
E Coli

In order to develop new antimicrobial agents, a series of 3-formyl indole based Schiff bases were synthesized by reacting 3-formyl indole(indole-3-carboxaldehyde) with substituted aniline taking ethanol as solvent. The reaction was carried in the presence of small amount of p-toluene sulphonic acid as catalyst.All the synthesized compounds were characterized by IR, 1H-NMR spectral analysis. All the synthesized compounds were evaluated for antimicrobial activity against two gram positive bacterial strains (B. subtilisand S. aureus) and two gram negative bacterial strains (P. aeruginosaand E. coli) and one fungal strain (C. albicans). All the synthesized compounds were found to have moderate to good antimicrobial activity. The  standard drug amoxicillin, fluconazole were used for antimicrobial activity. Among the synthesized compounds, the maximum antimicrobial activity was shown by compounds GS04, GS07, GS08 and GS10.

Disinfection of Fruits with Activated Water

2019 ◽  
Vol 10 ◽  
pp. 1864-1872
Author(s):  
Prof. Teodora P. Popova
Keyword(s):  
Antimicrobial Activity ◽  
Aqueous Solutions ◽  
Antimicrobial Properties ◽  
The Other ◽  
Gram Negative Bacteria ◽  
High Antimicrobial Activity ◽  
Gram Negative ◽  
E Coli ◽  
Number Of Microorganisms ◽  
Lower Effect

The effect of ionized aqueous solutions (anolytes and catholyte) in the processing of fruits (cherries, morellos, and strawberries) for decontamination has been tested. Freshly prepared analytes and catholyte without the addition of salts were used, as well as stored for 7 months anolytes, prepared with 0.5% NaCl and a combination of 0.5% NaCl and 0.5% Na2CO3. The anolyte prepared with a combination of 0.5% NaCl and 0.5% Na2CO3, as well as the anolyte obtained with 0.5% NaCl, exhibit high antimicrobial activity against the surface microflora of strawberries, cherries, and sour cherries. They inactivate E. coli for 15 minutes. The other species of the fam. Enterobacteriaceae were also affected to the maximum extent, as is the total number of microorganisms, especially in cherries and sour cherries. Even stored for 7 months, they largely retain their antimicrobial properties. Anolyte and catholyte, obtained without the addition of salts, showed a lower effect on the total number of microorganisms, but had a significant effect on Gram-negative bacteria, and especially with regard to the sanitary indicative E. coli.

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